In fiber reinforced composite, glass fiber reinforced plastics (GFRP) are widely
used. But they have a disadvantage from the viewpoint of reuse and recycling.
Instead of GFRP, natural fibers such as bamboo, jute, kenaf and hemp fibers are
focused upon for environmental friendliness.
In this study, jute fiber is chosen as reinforcement because of the huge market
and low cost. Polypropylene and emulsion type biodegradable resins are used as
the matrix because of their recycling properties and cost. The tensile properties
for Jute Fiber Reinforced Plastics (JFRP) are examined.
There are few reports about strength reduction from the viewpoint of residual
strain and damage accumulation. So in this study, cyclic loading (load-unload)
tests were conducted for improving the mechanical properties. Heat treatment is
also conducted for JFRP to examine the strength.
As a result, the following conclusions are obtained. Young’s modulus is
improved for load-unload tensile tests. In the case where the load is less than
75% of the ultimate load and the number of cycles is ten, the residual strain has
no effect on the tensile strength after load-unload tests. In the case where the
load is 82.5% of the ultimate load, the tensile strength decreased. In the case
where the load-unload test used 50% and 70% of the ultimate load, the residual
strains are 0.12% and 0.40% respectively. There is no effect for tensile strength
in the case where heat treatment is conducted to the pre-preg using PLA resin.
Keywords: jute fiber, polypropylene, green composite, tensile strength.
1 Introduction
Fiber Reinforced Plastics (FRP) is widely used for airplanes, automobile parts,
fishing rods, bathtubs and many other engineering products. However, recently
there have been some environmental problems, especially with the disposal of